1. Field of the Invention
The present invention relates to an imaging apparatus having a solid-state imaging device such as a charge coupled device (CCD) and a method of controlling an imaging apparatus.
2. Related Art
In general, imaging apparatuses such as digital video cameras are equipped with solid-state imaging devices such as CCD or complementary metal-oxide semiconductor (CMOS) as imaging devices. Such solid-state imaging devices convert imaging light from the subjects into analog electrical signals by each of the pixels. Further, the imaging apparatuses convert the analog electrical signals into digital signals, and store the data of the converted digital signals in storage devices or display the data of the converted digital signals on display devices as images.
FIG. 7 shows an example of a part of the configuration of an imaging apparatus 11. The imaging apparatus 11 shown in FIG. 7 is provided with an optical system 21 composed of lenses and the like, a solid-state imaging device 31, an analog signal processing section 51, an A/D converter 61, an image processing section 71, and a controller 81. It should be noted that the analog signal processing section 51, the A/D converter 61, the image processing section 71, and the controller 81 form a signal processing section 41.
The optical system 21 focuses the incident light from the subject into an image on the solid-state imaging device 31. The analog signal processing section 51 retrieves image data from the analog electrical signal converted by the solid-state imaging device 31. Further, the A/D converter 61 connected to the analog signal processing section 51 converts the analog electrical signal into digital image data.
The image processing section 71 connected to the A/D converter 61 performs various image processes such as gray-scale conversion, white balance correction, and γ-correction process, and an image process such as YC (luminance-chrominance) conversion process on the digital image data. As described above, the controller 81 performs control of the analog signal processing section 51, the A/D converter 61, and the image processing section 71 forming the signal processing section 41.
The digital image data thus processed with the image processes can separately be stored in a storage device not shown or displayed on a monitor as a display device.
Incidentally, the solid-state imaging device 31 of the imaging apparatus 11 shown in FIG. 7 is composed of CCD. In the CCD, a color filter is provided to each of the pixels so as to achieve imaging of color images. Further, in order for improvement of color reproducibility and enhancement of sensitivity, each of the pixels is provided with an infrared filter for transmitting an infrared component.
Therefore, as shown in FIG. 2B, a filter 3a is provided on the front surface of the solid-state imaging device 31 (3) connected to the signal processing section 41. As shown in FIG. 2A, the filter 3a is composed of totally four kinds of filters including three kinds of color filters R, B, and G for respectively transmitting red light, blue light, and green light in the visible region, and an infrared filter IR for transmitting light in the infrared region.
As shown in FIG. 2A, the filters R, B, G, and IR are arranged in a mosaic manner in the filter 3a to form a single filter with four kinds of filters. This single filter is provided for each of the pixels. In other words, four light-sensitive devices for respectively receiving the four kinds of wavelengths of light beams, namely red, blue, green, and infrared, form a unit of a single pixel . Further, the four light-sensitive devices are provided with respective one of the color filters R, B, and G, and the infrared filter IR.
As related art documents, for example, JP-A-2001-69519, JP-A-2005-6066, and JP-A-11-289491 can be cited.